In web offset printing presses, printing units may print text and images on a web substrate. A folder may fold the printed web and cut the printed web into a plurality of signatures. The folder may include one or more angle bars that guide and reorient the web for folding and cutting. The angle bars may each be provided internally with air by an air source and direct the air towards the passing web through holes formed in an outer surface of each angle bar. The air may eliminate friction between the angle bars and the web to improve transport of the web through a printing press and to prevent the web guiding device from marking the web.
In printing presses where the web is reoriented from traveling in a horizontal orientation (parallel to the ground) to a vertical orientation (traveling on one side, perpendicular to the ground) a relatively long length of the web is acted on by several lead rolls and a ninety degree angle bar to reorient the web. Examples of such arrangements are disclosed in commonly owned U.S. patent application Ser. Nos. 12/322,738, 12/322,767, 12/322,768 and 12/322,775. The use of the relatively long length of traveling web may contribute to difficulties in control, formation of wrinkles in the web and errors in the lateral position as the reoriented web travels away from the angle bar. Also, the use of ninety degree angle bars in multiple web configurations may sometimes lead to web congestion. Web guides may also sometimes be used to control web position.